[for-next][PATCH 13/18] sparc/function_graph: Simplify with function_graph_entry()

From: Steven Rostedt
Date: Wed Nov 21 2018 - 19:34:54 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

The function_graph_entry() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().

Have sparc use the new code, and remove the shadow stack management as well as
having to set up the trace structure.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: sparclinux@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxx
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
arch/sparc/kernel/ftrace.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/sparc/kernel/ftrace.c b/arch/sparc/kernel/ftrace.c
index 915dda4ae412..684b84ce397f 100644
--- a/arch/sparc/kernel/ftrace.c
+++ b/arch/sparc/kernel/ftrace.c
@@ -126,20 +126,11 @@ unsigned long prepare_ftrace_return(unsigned long parent,
unsigned long frame_pointer)
{
unsigned long return_hooker = (unsigned long) &return_to_handler;
- struct ftrace_graph_ent trace;

if (unlikely(atomic_read(&current->tracing_graph_pause)))
return parent + 8UL;

- trace.func = self_addr;
- trace.depth = current->curr_ret_stack + 1;
-
- /* Only trace if the calling function expects to */
- if (!ftrace_graph_entry(&trace))
- return parent + 8UL;
-
- if (ftrace_push_return_trace(parent, self_addr, &trace.depth,
- frame_pointer, NULL) == -EBUSY)
+ if (function_graph_enter(parent, self_addr, frame_pointer, NULL))
return parent + 8UL;

return return_hooker;
--
2.19.1